Contained Landfill Chapter 13

1. Contained LandfillChapter 13 Kentucky Department of Environmental Protection Division of Compliance Assistance 300 Fair Oaks Lane • Frankfort, KY 40601 Phone: 502.564.0323 • 800.926.8111 • Fax: 502.564.9720 Email: envhelp@ky.gov • Website: dca.ky.gov

2. Laurel Ridge Contained Landfill

3. What are the design requirements and gas and leachate regulations for a Contained Landfill?

4. Chapter 13 General Objective Describes the typesof acceptable waste, design requirementsand operational requirements for Contained Landfills.

5. Chapter 13 Specific Objectives • Understand the minimum siting and design standards for a contained landfill. • Define possible solutions to address problems with storm water control. • List methods of operations for Contained Landfills.

6. Chapter 13 Specific Objectives • Explain what can be done to protect the liner of a newly constructed contained landfill. • List and describe the purpose of the final cap components. • Describe the closure and closure care requirementsof a contained landfill.

7. Chapter 13 Specific Objectives • Understand leachate regulations associated with a contained landfill. • Comprehend types of cover and whenit should be used. • Explain random inspections and specially designated handling areas.

8. Buffer Zone Requirements Siting or buffer zone requirements specified for Contained landfills are identical to those specified for Residual and CDD Landfills in 401 KAR 48:050.

9. Siting Requirements • Flood Plains – sites cannot • Restrict the flow of the 100-year flood • Reduce the temporary water storage capacity of the flood plain. • Operational methods at the site must prevent waste washout

10. Buffer Zone Requirements The distance between the fill area and the following must be: • Property line (100 feet) • Intermittent or perennial stream (Unless a water quality certification is issued) (250 feet) • Sinkhole or other similar feature of karst terrain (250 feet) • Wastes cannot be placed in the zone of collapse of deep mine workings or within the critical angle of draw of such workings.

11. Design Requirements: Minimum Criteria • 401 KAR 48:070; 48:080 (technical requirements) • This module outlines the minimum design standardsfor the liner and cap in contained landfills.

12. Design Requirements: Owners or operators MUST ensure that the design: • Maintains the separation of surface water and leachate. The contours of the landfill must minimize the surface water that runs on or through the landfill • Allows ditches to withstand a 100-year, 24 hour storm flow(runoff from a 6 to 7 inch rainfall)

13. Design Requirements: Owners or operators MUST ensure that the design: Meets the same requirements for CDD landfill sediment basins plus the following: • The downhill toe of the slope of the sediment pond dam must be 50 feet from the property line • Enables the landfill to resist an earthquake event (seismic) if it is constructed in the seismic impact zone

14. Design Requirements: Owners or operators MUST ensure that the design: • Ensures the stability of the system components (i.e., liner, leachate collection system, cover, liner, and cap) (i.e., karst, underground mines, unstable slopes) • Ensures that sufficient equipment be onsite to compact wastes received within 2 hours of receipt. Backup equipment must be available within 24 hours. A recordkeeping system must be proposed to address equipment maintenance. • Ensures an in-place waste density of at least 1,200 pounds per cubic yard, (except fluff lift or protective cover)

15. Design Requirements: Owners or operators MUST ensure that the design: • Addresses soil availability to meet the liner and cap construction needs (soil volumes and permeability as well as operational cover) • Includes a building for personnel which is: • Heated • Air-conditioned or screened • Drinking water and sanitary facilities. • Includes a building which is large enough to hold the largest piece of equipment for maintenance

16. Design Requirements: Owners or operators MUST ensure that the design: • Ensures that each building has a monitoring alarm system to detect explosive gases • Outlines a quarterly explosive gas (methane) monitoring program which addresses: • The control of explosive gases meeting the EPS of 401 KAR 47:030 • Soil and water properties of the area around the landfill, • Possible gas migration • Location of facility structures and boundaries • Gas venting system with minimum of one vent per acre (passive gas system) • Location of surrounding off-site structure and residences

17. Design Requirements: Owners or operators MUST ensure that the design: • Meets the following roadway requirements: • Construction of a road from the publicly maintained highway to the waste disposal area • Construction of an all-weather perimeter road (gravel or paved) around the landfill to each monitoring and sediment control structure • Internal roads must be all weather and designed to within 200 feet of the working face

18. Design Requirements: Owners or operators MUST ensure that the design: • Meets the following roadway requirements: • All roads must be designed wide enough to allow passage of vehicles, carry normal traffic, and properly drain • Entry to landfill must have enough space to safely accommodate trucks and prevent delays on the public roadway (include stacking lanes).

19. Design Requirements: Owners or operators MUST ensure that the design: • Has a safety and communication plan which addresses: • Heavy equipment safe operation and maintenanceto prevent accidents and breakdowns • Description of: • Communication equipment such as radios, mobile phones and base telephones (i.e., cell phones), • Fire fighting procedures • OSHA-related requirements

20. Design Requirements: Owners or operators MUST ensure that the design: • Has scales to weigh all waste • Has a leachate collection and treatment system meeting the same requirements as a CDD landfill, except that possible treatment in ponds before discharge is not allowed

21. Liner System Starting from the bottomand going up: • A sub-grade: the landfill sub-grade is the upper rock layer, soil layer, or select fill that is the foundation to support the liner. • Graded according to plan • Sufficiently dry and stable • Proof-rolled • Free of organic material • Soil embankment used to construct subgrade is verified by a minimum of 9 tests per acre to determine sub-grade compaction of 92%. Sufficient cross sections must be taken to document the finished elevation.

22. Liner System Starting from the bottomand going up: • For all areas, a composite liner with:. • 10% slope minimum • 36” thick clay layer with permeability of 1 X 10-7 cm/sec OR 24” thick for slopes 4:1 or greater • 60 mil thick synthetic (geomembrane) layer • 12” drainage layer with permeability of 1 X 10-3 cm/sec (sand)

23. Liner System Starting from the bottomand going up: • For all areas, a composite liner with:. • Filter fabric to protect the drainage layer (this may be removed upon approval of an alternative specification) • Geocomposite, a synthetic drainage netting heat-fused to upper and lower filter fabrics, may replace the drainage layer on slopes greater than 10% • Geosynthetic Clay Liner (GCL) placed on a 24” compacted soil liner may replace the low permeable soil liner requirement. Compacted soil liner shall meet 1 x 10-7 cm/sec permeability in the laboratory.

24. Liner System Starting from the bottomand going up: • A Leachate Collection System that uses: • A maximumstatic head of 12” of depth • 8” diameter schedule 80 plastic pipe (or equivalent) for the main collection lines or another design that meets the 12” maximum leachate depth rule • 4” lateral lines installed perpendicular to flow or another design that meets the 12” maximum leachate depth rule

25. Liner System Starting from the bottomand going up: • A Leachate Collection System that uses: • A design for the pipes to withstand all encountered static and dynamic load (dead and live loads) • A 1% minimum slope for piping • A leachate collection tank with the same amount of storage as a CDD landfill

26. Liner System Starting from the bottomand going up: • A Leachate Collection System that uses: • An identified and assured disposal method (letter of acceptance from an off site Publicly Owned Treatment Works (POTW)) • Allowances for inspection and cleaning.

27. Contained Landfill Design Cross-Section Sloped Areas

28. Contained Landfill Design Cross-Section Geosynthetic Clay Liners (GCL)

29. Leachate Reduction: Problems Documented problems with the design and operation of leachate collection systems at contained landfills. • Failure to divert rainfall run-on and runoff away from the leachate collection layer overloaded the systems with rainwater and dilute leachate that nevertheless must be transported to a POTW for disposal (similar to mixing storm water and sewage).

30. Leachate Reduction: Problems Documented problems with the design and operation of leachate collection systems at contained landfills. • This results in an enormous increase in hauling and treatment costs or increases temptation to directly discharge to a stream. One company performed open dump clean up work over$1M in response to illegal discharges.

31. Leachate Reduction: Solutions Solutions include: • The design and installation of plastic liner flaps between the new liner area and the current disposal area • Construction of a smaller cell since plastic encourages runoff (one year maximum is recommended) • Installing partial berms between cells to separate leachate flows from filled area from surface water in new area

32. Leachate Reduction: Solutions Solutions include: • Covering the entire new cell with waste and interim cover while directing rain water (runoff) from the top of the interim cover through the sediment pond • The design and installation of a drain pipe through the dam at the bottom of the landfill for storm water gravity flow (less expensive than pumping but must seal prior to filling)

33. Leachate Reduction: Solutions Solutions include: • The design and installation of temporary runoff ditches from the covered working area to the main runoff ditches connecting to the sediment pong (Designed by a Professional Engineer per 401 KAR 48:070, Section 7(2)(c)) • Partnering the consulting engineer and the manager to sequence filling, (i.e., onsite visits to look at the current situation and plan a way out for the storm water as filling progresses)

34. Methods of Operation • Plan to deposit refuse in a method that reduces leachate production andlitter • Prepare a waste dumping berm high enough for the protective layer and first waste layer • Spread refuse using light weight equipment (such as a D-6 dozer or equivalent) • Continue placing next lift normally using a landfill compactor

35. Liner Protection The Cabinet requires protection of the newly constructed contained landfill liner to prevent boards, pipes and other potentially damaging material from puncturing the liner. This is even more important as more designers specify GCL and geocomposite drainage netting instead of CCL (2 or 3 feet of clay) and 1 foot of gravel.

36. Liner Protection • The new GCL material is: • More resistant to water infiltration, • Thinnerthan traditional clay liner • Typically less than ½” thick (compared to the 24-36” thick normal liner • Drainage geocomposite is also much thinner

37. Options for GCL/Geocomposite Liner • Placing 6 - 12” of sand or gravel on top of the GCL/drainage net • Placing 8 feet of “fluff” which is household garbage free of any damaging objects, such as boards or pipes, on top of the 12” thick drainage layer or sand/gravel protective layer

38. Options for GCL/Geocomposite Liner • Placing 8’of “fluff” may require: • Route management so that haulers pick up no boards, pipes, CDD material, swing sets, etc. during the time of fluff layer placement • Diversion of CDD waste trucks to the CDD landfill unit • Spotters to remove objects on the floor of the cell to remove damaging objects • Use of a D-6 dozer (or equivalent) or smaller equipment for spreading

39. Final Cap • The cap is a layered system which must maintain a slope between 5% and 25%. • The components of the cap (from bottom to top) are: • Filter fabric • Twelve inch thick sand gas venting system with a minimum hydraulic permeability of 1 x 10-3 cm/sec, or geocomposite (passive system only) • Filter fabric to protect the venting system

40. Final Cap • The components of the cap (from bottom to top) are: • 18” thick clay layer with a minimum permeability of 1 x 10-7 cm/sec • For areas with a slope of less than 15%, a 12” thick drainage layer with a permeability of 1 x 10-3cm/sec sand, gravel, or geocomposite • A 36” thick vegetative cover

41. Final Cap (continued) • The components of the cap (from bottom to top) are: • 18” thick clay layer with a minimum permeability of 1 x 10-7 cm/sec • For areas with a slope of less than 15%, a 12” thick drainage layer with a permeability of 1 x 10-3cm/sec sand, gravel, or geocomposite • A 36” thick vegetative cover

42. Landfill Gas Regulations • Maintenance Equipment: The owner or operator shall provide the landfill equipment required to maintain methane gas systems (401 KAR 48:070, Section 6(3)(d)) • Buildings: Each building shall have an alarm installed in accordance with the manufacturer’s recommendations to detect the presence of explosive gases(401 KAR 48:070, Section 9(3))

43. Landfill Gas Regulations • Explosive Gas Program: The application for a contained landfill unit shall include a quarterly methane monitoring program to ensure meeting the standards of 401 KAR 47:030, Section 11 • The minimum monitoring frequency shall be quarterly • A gas venting system shall be designed for all landfillsA minimum of one vent shall be required per acre of landfill (passive system only) to be filled (401 KAR 48:070, Section 10; similar to 40 CFR 258.23)

44. Landfill Gas Regulations Alternative Specifications . . . may be used only afterapproval by the Cabinet upon a demonstration by a qualified registered professional engineer that they shall result in performance with regard to safety, stabilityand environmental protection equal to or better than that resulting from designs complying with the specifications of 401 KAR 48:080, Section 11

45. Cover Requirements Contained landfills are required to use 3 types of cover: • Daily Cover • Interim Cover • Long-Term Cover The type used depends on the amount of time it will be used as a cover for wastes

46. Cover Requirements: Daily Cover • 401 KAR 48:090, Section 3(1) • Requires: • Acompacted layer of at least 6” of soil to cover all exposed wastes at the end of each operating day • Orfor continuously operating landfills, once every 24 hours • Primary cover materials are soil, properly weathered or crushed shale or siltstone

47. Cover Requirements: Daily Cover • Daily cover must: • not allow waste to protrude except for occasional litter not exceeding 10% of the cover area • be placed and compacted to allow for proper drainage • The owner or operatormay remove daily cover to allow methane gas to escape or for the removal of leachate • Any daily cover removed must be disposed of as a waste

48. Cover Requirements: Interim Cover 401 KAR 48:090, Section 3(2) REQUIRES: • The placement of an additional 6” of cover material over an area not set to receive additional solid waste within 30 calendar days • Including the previously applied daily cover, this would result in a cover depth of 12 inches • Interim cover should be placed, compacted, and graded to allow proper drainage and should be protected by temporary erosion controls • Interim cover must be properly seeded during the fall seeding season

49. Cover Requirements: Interim Cover • Placement of interim cover normally means that the operator will utilize the area for disposal again in the near future • On the day waste is to be placed over an area that has interim cover, up to 6” of cover may be removed from the area of the cell for that day’s operation

50. Cover Requirements: Long-Term Cover 401 KAR 48:090, Section 3(3) REQUIRES: • the operator to apply an additional 18” of cover over all areas not scheduled to receive additional wastes • Within 4 months • By September 15 of each year • This will increase the depth, including daily and interim cover, to a total of 30”